Guide wire

ABSTRACT

[Object] To provide a guide wire capable of obtaining excellent reshapability, while securing sufficient flexibility, at a distal part thereof. 
     [Solving Means] The guide wire  1  has a wire body  10  including a first wire  2  disposed on the distal side and a second wire  4  joined to the proximal end of the first wire  2 , and a helical coil  5  is disposed at a distal part of the wire body  10 . The first wire  2  includes a reshapable section  3 , a transition section  27 , a distal-side constant outer diameter section  26 , a first tapered section  22 , a constant outer diameter section  21 , a second tapered section  23  and a large diameter section  24 , in this order from the distal end side. The reshapable section  3  is plate-like in shape, and is used in the state of being deformed into a desired shape (in a reshaped state). The reshapable section  3  is provided in its upper surface with five grooves  31   a  to  35   a  extending in the plate width direction of the reshapable section  3  and located at intervals along the longitudinal direction of the reshapable section  3 . Of the reshapable section  3 , the portion where the grooves  31   a  to  35   a  are formed is more susceptible to plastic deformation than the other part.

TECHNICAL FIELD

The present invention relates to a guide wire.

BACKGROUND ART

Guide wires are used to insert and guide to a target site a catheter for use in treatment of cites at which open surgeries are difficult or which require low invasiveness to the body or in examination or treatment of a cardiac disease through cardioangiography or the like.

For example, in the process of PCI (Percutaneous Coronary Intervention), a treatment is conducted as follows. The distal end (tip) of a guide wire while kept protruding from the distal end of a balloon catheter is inserted together with the balloon catheter to a position immediately on the proximal side of a stenosed portion of the coronary artery, which portion is the target site, under fluoroscopic observation. Next, the distal end of the guide wire is passed through the stenosed portion. Thereafter, the balloon of the balloon catheter is guided to the stenosed portion while kept along the guide wire, and the balloon is dilated to dilate the stenosed portion, thereby securing a quantity of bloodstream.

For instance, in order to insert a guide wire from a femoral artery and to advance it through an aorta, an aortic arch and a coronary artery orifice into the coronary artery by the Seldinger technique, it is desirable that the guide wire be excellent in flexibility for following the track of the blood vessels (trackability) and in pushability which ensures effective transmission of a pushing force from the operator's hand side (the proximal side) to the distal part of the guide wire.

In addition, for the purpose of advancing the guide wire into a desired branch at a branching part of the coronary artery or the like, a distal part of the guide wire may in some cases be shaped in conformity with the shape of the branching part. Such a shaping operation is ordinarily performed with the surgeon's fingers at the time of surgery, and is called “reshaping”.

Especially, in the case of inserting the distal end of a guide wire into the coronary artery on the peripheral side, it may in many cases be impossible to select the desired branch while using the angle- or J-type tip shape of the guide wire preformed according to the related art, and the guide wire tip may be reshaped into a desired shape and then inserted again. When the shape of the guide wire tip is not satisfactory for the intended selection of the desired branch, it is necessary to once evulse the guide wire from the catheter, to reshape the guide wire tip again and to insert the guide wire again.

Meanwhile, there is known a guide wire in which a wire body is included of a Ni—Ti alloy exhibiting superelasticity, for obtaining flexibility at the distal part of the guide wire. In this case, however, the superelasticity of the distal part of the wire body makes the reshaping difficult. In view of this, there has been developed a guide wire having a reshapable distal part, as follows.

A guide wire in which a distal part of a core wire (wire body) included of a superepastic alloy has been deprived of (or degraded in) superelasticity by a heat treatment has been disclosed (refer to, for example, Patent Document 1).

In the case where the distal part is deprived of superelasticity by a heat treatment, however, the distal part provided easily with a new shape upon reshaping may return to its original shape by loosing the new shape upon being inserted into a living body. This is because the superelastic alloy tends to return to its original straight shape due to its own shape memory effect. More specifically, the heat treatment raises the transformation point of the distal part, and the heat-treated part does not exhibit superelasticity at room temperature, so that this part can be shaped as if it were plastically deformed. However, the deformation in this instance is an apparent plastic deformation; therefore, when the reshaped part is inserted into the living body and is warmed up to the body temperature, its transformation point is approached and it would return to the original straight shape.

Besides, a guide wire in which a distal part of a core wire (wire body) is deprived of superelasticity by strong working has been disclosed (refer to, for example, Patent Document 2).

In the case where superelasticity is thus lost by strong working, however, the effect may often be unsatisfactory, so that reshaping may be difficult to achieve. In addition, the worked part may become harder than required, thereby lowering the flexibility of the distal part of the guide wire. In order to enhance the flexibility, it may be contemplated to set a flat plate-like section (reshapable section) to be thinner. In that case, however, the strength of the flat plate-like section cannot be maintained. Since the guide wire tip may be advanced through a stenosed portion while being rotated or may be pulled in a bent state, it must have a strength (e.g., tensile strength) of not lower than a certain value. Therefore, there is a limit to the thinning of the flat plate-like section. Accordingly, by this approach it is impossible to secure both flexibility and strength.

[Patent Document 1]

Japanese Patent Laid-open No. Hei 5-168717

[Patent Document 2]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention

It is an object of the present invention to provide a guide wire in which excellent reshapability can be obtained while securing sufficient flexibility at a distal end (tip) part thereof.

Means for Solving the Problems

The above object is attained by the present invention as set forth in the following (1) to (6). Besides, the following (7) to (22) are preferable.

(1) A guide wire including a wire body having an elongate reshapable section at a distal part thereof,

wherein a surface of said reshapable section is provided with a plurality of grooves extending in a direction different from the longitudinal direction of the reshapable section.

(2) The guide wire as set forth in (1) above, wherein the reshapable section is plate-like in shape, and is provided with the grooves in at least one side of the plate-like shape thereof.

(3) The guide wire as set forth in (1) above, wherein the reshapable section is plate-like in shape, and is provided with the grooves in the same pattern or different patterns respectively in both sides of the plate-like shape thereof.

(4) The guide wire as set forth in (3) above, wherein the reshapable section is provided with the grooves alternately in one side of the plate-like shape thereof and in the other side of the plate-like shape thereof.

(5) The guide wire as set forth in any of (2) to (4) above, wherein the reshapable section has a part where the plate thickness and/or the plate width thereof decreases, continuously or stepwise, along the distal direction.

(6) The guide wire as set forth in (1) above, wherein the reshapable section is bar-like in shape, and is provided with the grooves in an outside surface thereof.

(7) The guide wire as set forth in (6) above, wherein the grooves are formed in an annular shape or a spiral shape.

(8) The guide wire as set forth in (1) above, wherein the reshapable section is bar-like in shape, and is provided with the grooves in the same pattern or different patterns respectively in a surface on one side thereof and in a surface on the other side thereof which surfaces are opposite to each other, with the center axis of the reshapable section therebetween.

(9) The guide wire as set forth in (8) above, wherein the reshapable section is provided with the grooves alternately in the surface on one side and in the surface of the other side.

(10) The guide wire as set forth in any of (6) to (9) above, wherein the reshapable section has a part where the outer diameter thereof decreases, continuously or stepwise, along the distal direction.

(11) The guide wire as set forth in any of (1) to (8) above, wherein the grooves are formed at intervals along the longitudinal direction of the reshapable section.

(12) The guide wire as set forth in (11) above, wherein the interval between the adjacent grooves decreases along the distal direction of the reshapable section.

(13) The guide wire as set forth in (11) or (12) above, wherein the depth of said groove increases or decreases along the distal direction of the reshapable section.

(14) The guide wire as set forth in (11) or (13) above, wherein the width of the groove increases or decreases along the distal direction of the reshapable section.

(15) The guide wire as set forth in any of (1) to (14) above, wherein all or some of the grooves are filled with a malleable metal.

(16) The guide wire as set forth in any of (1) to (15) above, wherein a part, inclusive of the reshapable section, of the wire body is included of a superelastic alloy.

(17) The guide wire as set forth in any of (1) to (16) above, wherein the wire body has a tapered section of which the outer diameter gradually decreases in the distal direction.

(18) The guide wire as set forth in (17) above, wherein the tapered section is formed on the distal side of and in the vicinity of the reshapable section.

(19) The guide wire as set forth in any of (1) to (18) above, further including a coil which covers the reshapable section.

(20) The guide wire as set forth in (19) above,

further including fixing materials for fixing the coil to the wire body at a plurality of locations,

wherein one of the plurality of fixing materials is disposed on the distal side of the reshapable section, and another of the plurality of fixing materials is disposed on the proximal side of the reshapable section.

(21) The guide wire as set forth in (19) or (20) above, further including a resin coating layer which covers the coil.

(22) The guide wire as set forth in (21) above, wherein an outer peripheral surface of the resin coating layer is provided with a groove at a portion corresponding to the reshapable section.

EFFECTS OF THE INVENTION

According to the present invention, it is possible to provide a guide wire of which a distal part can be easily and assuredly reshaped into a desired shape while securing sufficient flexibility of its distal part and which is excellent in reshapability.

Especially, in the present invention, with the reshapable section provided partly with the grooves, only the portions of the grooves can easily be deformed (plastically deformed). Therefore, it is possible to avoid the situation in which the whole part of the reshapable section is hardened more than required, thereby lowering the flexibility or elasticity of the distal part of the guide wire.

Besides, by appropriately setting the shape (the plate thickness, the plate width, the outer diameter, etc.) of the reshapable section, the portions where the grooves are formed (formation pattern), the density of the grooves (which depends on the groove pitch (the interval between the adjacent grooves), the groove width, etc.), the degree of plastic deformability at the portions where the grooves are formed (which depends on the locations of the grooves, the groove depth, the material properties of the portions where the grooves are formed, etc.) and the like factors, it is ensured that a desired portion (for example, a portion on the distal side) of the reshapable section can be reshaped into a more complicated or finer shape.

BEST MODE FOR CARRYING OUT THE INVENTION

Now, the guide wire according to the present invention will be described in detail below, based on preferred embodiments shown in the accompanying drawings.

First Embodiment

FIG. 1 is a partial longitudinal sectional view (schematic side view) showing a first embodiment of the guide wire according to the present invention, FIG. 2 is a side view of a reshapable section of the guide wire shown in FIG. 1, and FIG. 3 is a plan view of the reshapable section shown in FIG. 2. Incidentally, for convenience of description hereinbelow, the right side in FIGS. 1 to 3 will be referred to as “proximal (side)”, and the left side as “distal (side)”; also, the upper side in FIGS. 1 and 2 will be referred to as “upper (side)”, and the lower side as “lower (side)”. In addition, for easy understanding, the guide wire in FIGS. 1 to 3 is schematically shown in the state of being shortened in the longitudinal direction and exaggerated in the diametral direction (thickness direction), so that the ratio between the size in the longitudinal direction and the size in the diametral direction in these drawings is different from the actual ratio (the same applies also to FIG. 4 and the latter figures).

The guide wire 1 shown in FIG. 1 is a catheter guide wire used in the state of being inserted in the lumen of a catheter (inclusive of endoscope), and includes: a wire body 10 having a construction in which a first wire 2 disposed on the distal side and a second wire 4 disposed on the proximal side of the first wire 2 are joined to each other; and a helical coil 5 disposed at a distal part (distal-side part) of the wire body 10. The whole length of the guide wire 1 is not particularly limited, and is preferably about 200 to 5000 mm.

The first wire 2 is included of a wire material which is flexible or elastic. In the present embodiment, the first wire 2 includes: a constant outer diameter section 21 which is substantially constant in outer diameter; a first tapered section 22 located on the distal side relative to the constant outer diameter section 21 and gradually decreasing in outer diameter along the distal direction; a distal-side constant outer diameter section 26 located on the distal side relative to the first tapered section 22; a plate-like transition section 27 located on the further distal side of the distal-side constant outer diameter section 26 and decreasing in thickness and increasing in width along the distal direction; a reshapable section 3 located on the further distal side of the transition section 27; a large diameter section 24 located on the proximal side relative to the constant outer diameter section 21 and larger in diameter than the constant outer diameter section 21; and a second tapered section 23 located between the constant outer diameter section 21 and the large diameter section 24 and gradually decreasing in diameter along the distal direction. These sections are sequentially disposed in the order of the reshapable section 3, the transition section 27, the distal-side constant outer diameter section 26, the first tapered section 22, the constant outer diameter section 21, the second tapered section 23 and the large diameter section 24, from the distal side of the first wire 2.

With the first tapered section 22 formed between the reshapable section 3 and the constant outer diameter section 21, particularly with the reshapable section 3 formed on the distal side of and in the vicinity of the first tapered section 22, the rigidity (flexural rigidity, torsional rigidity) of the first wire 2 can be gradually reduced along the distal direction. As a result, the guide wire 1 is provided with a good stenosed portion passing property and flexibility at a distal part thereof, whereby trackability in regard of blood vessels and the like and safety are enhanced, and kinking and the like can be prevented.

In addition, like in the case of the first tapered section 22, with the second tapered section 23 disposed so that the constant outer diameter section 21 and the large diameter section 24 are connected therethrough, the rigidity (flexural rigidity, torsional rigidity) of the first wire 2 can be gradually decreased along the distal direction.

Incidentally, the taper angle (the rate of decrease in outer diameter) of the first tapered section 22 (also of the second tapered section 23) may be constant along the longitudinal direction of the wire body 10 or may vary along the longitudinal direction at part of the first tapered section 22. For example, a plurality of portions having a comparatively large taper angle (rate of decrease in outer diameter) and a plurality of portions having a comparatively small taper angle may be formed alternately and repeatedly.

Besides, there may be differences in taper shape and/or taper angle, between the first tapered section 22 and the second tapered section 23.

The reshapable section 3 configured as described below is formed, on the distal side of the first tapered section 22, with the distal-side constant outer diameter section 26 and the transition section 27 therebetween, and preferably as one body with the first tapered section 22. Here, the first wire 2, in its whole body inclusive of the reshapable section 3, is integrally formed of the same material; as will be described later, a preferable material constituting the first wire 2 is a superelastic alloy (an alloy exhibiting pseudo-elasticity) represented by Ni—Ti alloy. Therefore, a preferable material of the reshapable section 3 is also a superelastic alloy, and such a case as this will be described below.

As shown in FIGS. 2 and 3, the reshapable section 3 is plate-like in shape, and can be used after deformed into a desired shape (after reshaping). Generally, a guide wire may in some cases be used after its distal part is preliminarily deformed by a surgeon or the like into a desired shape, for the purpose of conforming a distal part of a catheter or the like to be guided to the shape of a blood vessel or for the purpose of achieving appropriate and smooth selection of and guide into a desired branch of blood vessel, and the bending of the distal part of the guide wire into a desired shape in this manner is called “reshaping”. With the reshapable section 3 provided, the reshaping can be carried out easily and assuredly, whereby operationality (manipulability) in inserting the guide wire 1 into a living body is enhanced remarkably.

The plate-like reshapable section 3 as above is provided in the upper surface (surface) thereof with a plurality of grooves extending in a direction different from the longitudinal direction of the reshapable section 3 (in this embodiment, the extending direction is a direction orthogonal to the longitudinal direction of the reshapable section 3, specifically, the extending direction is the plate width direction of the reshapable section 3), at intervals along the longitudinal direction of the reshapable section 3. More specifically, as shown in FIGS. 2 and 3, the reshapable section 3 is provided with a total of five grooves 31 a, 32 a, 33 a, 34 a and 35 a, in this order from the distal side.

Of the reshapable section 3, the portions where the grooves 31 a to 35 a are formed (hereinafter referred to as “groove formed portions”) are smaller than the other portions (for example, portions 36 between the adjacent grooves, and a portion 37 on the distal side relative to the groove 31 a) in plate thickness of the reshapable section 3. Therefore, when the reshapable section 3 is reshaped, the groove formed portions are more susceptible to deformation (plastic deformation) than the other portions. Accordingly, the reshapable section 3 can be reshaped into a desired shape easily and assuredly, and the shape upon reshaping is maintained. The reshapable section 3 thus reshaped into the desired shape keeps the shape upon reshaping, not only at normal temperature but also when its temperature is raised roughly to a body temperature.

Besides, in the present invention, since the reshapable section 3 is provided partly with the grooves 31 a to 35 a so as to render the groove formed portions susceptible to plastic deformation, it is possible to avoid the situation in which the reshapable section 3 as a whole is hardened more than necessary, thereby lowering the flexibility or elasticity of a distal part of the guide wire 1. Furthermore, the reshapable section 3 as a whole may be deprived of elasticity (be rendered susceptible to plastic deformation) by subjecting the reshapable section 3 to a heat treatment.

The degree of plastic deformation of the grooves 31 a to 35 a at the time of reshaping is not particularly limited, and may be, for example, as follows. As shown in FIG. 2, let the bending angle when the portion near the groove 33 a is bent into an “inverted V shape” in the direction of opening the groove 33 a be +α°, and let the bending angle when the portion near the groove 33 a is bent into a “normal V shape” in the direction of closing the groove 33 a be −α°, and the same is applied also to the other four grooves 31 a, 32 a, 34 a and 35 a, then the distal end of the reshapable section 3 can be bent to an angle of ±5α° at maximum relative to the proximal end of the reshapable section 3, through the bending at the total of five grooves 31 a to 35 a. For example, where α is 180, the distal end of the reshapable section 3 can be so bent as to be substantially perpendicular to the proximal end of the reshapable section 3 (the reshapable section 3 can be bent into L shape). In addition, where α is 360, the distal end of the reshapable section 3 can be so bent as to be reversedly directed toward the proximal end of the reshapable section 3 (the reshapable section 3 can be bent into U shape). The value of α can be adjusted, as desired, by selecting the shapes and dimensions (length, width, depth, etc.) of the grooves 31 a to 35 a, the number of the grooves formed, the pattern in which the grooves are formed, and the like conditions.

Incidentally, the shape of the reshapable section 3 upon reshaping is not limited to the L shape and the U shape (J shape), and may be any of other shapes such as S shape and three-dimensional shapes.

Let the intervals (mean values) between the adjacent ones of the grooves 31 a to 35 a in the reshapable section 3 be respectively T1, T2, T3 and T4 (see FIG. 2), then the values of T1, T2, T3 and T4 are substantially equal in the configuration shown in FIG. 2. In other words, the grooves 31 a to 35 a are formed at a fixed pitch (at regular intervals) along the longitudinal direction of the reshapable section 3. In the present invention, however, the intervals (T1, T2, T3 and T4) between the adjacent grooves may all be different, or some of them may be different from the others.

Examples of the just-mentioned configuration include the case where the interval between the adjacent grooves decreases in the distal direction in some part of the reshapable section 3, i.e., the intervals T1, T2, T3 and T4 satisfy the relationship of T1≦T2≦T3≦T4 (exclusive of the case of T1=T2=T3=T4). Such a configuration permits the reshapable section 3 to be reshaped more finely as the distal end is approached, which naturally is preferable. In other words, since the density of the grooves formed in the reshapable section 3 is higher on the distal side than on the proximal side, the reshapable section 3 can be reshaped into a more complicated shape or finer shape (for example, into a more acutely curved or bent shape) on the distal side than on the proximal side.

Incidentally, the practical values of T1, T2, T3 and T4 are preferably about 0.1 to 2 mm, more preferably about 0.5 to 1 mm.

Besides, in the configuration shown in FIG. 2, the depths of the grooves 31 a to 35 a in the reshapable section 3 are substantially equal. In the present invention, however, the depths (mean values) of the grooves 31 a to 35 a may all be different, or some of them may be different from the others.

Examples of the just-mentioned configuration include the case where the groove depth increases (or decreases) in the distal direction in some part of the reshapable section 3, i.e., the depths (mean values) D1, D2, D3 and D4 (not shown) of the grooves 31 a, 32 a, 33 a, 34 a and 35 d satisfy the relationship of D1≧D2≧D3≧D4 (exclusive of the case of D1=D2=D3=D4). Such a configuration permits the reshapable section 3 to be bent at sharper angles (more acutely) and be reshaped more finely, as the distal end is approached, which naturally is preferable. In other words, the reshapable section 3 can be reshaped into a more complicated shape or finer shape (particularly, a more acutely curved or bent shape) on the distal side than on the proximal side.

In addition, in the present invention, a configuration may be adopted in which, contrary to the above configuration, the groove depth decreases in the distal direction in some part of the reshapable section 3, i.e., the depths of the grooves satisfy the relationship of D1≦D2≦D3≦D4 (exclusive of the case of D1=D2=D3=D4).

Incidentally, the practical values of D1, D2, D3 and D4 are preferably about 0.001 to 0.03 mm, more preferably about 0.003 to 0.01 mm.

Besides, in the configuration shown in FIG. 2, the widths of the grooves 31 a to 35 a in the reshapable section 3 are substantially equal. In the present invention, however, the widths (mean values) of the grooves 31 a to 35 a may all be different, or some of them are different from the others.

Examples of the just-mentioned configuration include the case where the groove width increases (or decreases) in the distal direction in some part of the reshapable section 3, i.e., the widths (mean values) W1, W2, W3 and W4 (not shown) of the grooves 31 a, 32 a, 33 a, 34 a and 35 a satisfy the relationship of W1≧W2≧W3≧W4 (exclusive of the case of W1=W2=W3=W4). Such a configuration permits the reshapable section 3 to be bent at sharper angles (more acutely) and be reshaped more finely, as the distal end is approached, which naturally is preferable. In other words, the reshapable section 3 can be reshaped into a more complicated shape or finer shape (particularly, a more acutely curved or bent shape) on the distal side than on the proximal side.

In addition, in the present invention, a configuration may be adopted in which, contrary to the above configuration, the groove width decreases in the distal direction in some part of the reshapable section 3, i.e., the widths of the grooves satisfy the relationship of W1≦W2≦W3≦W4 (exclusive of the case of W1=W2 W3=W4).

Besides, the width of each of the grooves 31 a to 35 a may be constant along the longitudinal direction of the groove, or may vary in some intermediate part. For example, each of the grooves 31 a to 35 a may be so configured that the groove width is larger (or smaller) at both end parts thereof (near edges of the reshapable section 3) than in a central part thereof.

Incidentally, the practical values of W1, W2, W3 and W4 are preferably about 0.06 to 0.5 mm, more preferably about 0.1 to 0.4 mm.

In addition, the cross-sectional shape of each of the grooves 31 a to 35 a is not particularly limited, and may be any shape, for example, U shape (arcuate shape), V shape, W shape, rectangular shape, or pentagonal shape.

In the present embodiment, the plate width of the reshapable section 3 is substantially uniform along the longitudinal direction. Specifically, at least the portions including the grooves 31 a to 35 a (groove formed portions), of the reshapable section 3, are substantially constant in plate width. The value of the plate width of the reshapable section 3 is not particularly limited, insofar as the reshapable section 3 can be contained in the inside space (gap 50) of the coil 5. In order to secure sufficient flexibility and appropriate strength, however, the plate width is preferably about 0.1 to 0.5 mm, more preferably about 0.15 to 0.35 mm.

Incidentally, in the present invention, the configuration in which the plate width of the reshapable section 3 is uniform along the longitudinal direction is not limitative; thus, the plate width may vary in some intermediate part of the reshapable section 3. For example, the groove formed portions of one or more of the grooves 31 a to 35 a (preferably, all of the grooves) may have an increased or decreased plate width, as compared with the other portions than the grooves of the reshapable section 3 (for example, the straight portions between the adjacent grooves, or the portion 37 on the distal side of the groove 31 a).

Besides, in the present embodiment, the plate thickness of the reshapable section 3 (the plate thickness of the portions excluding the grooves 31 a to 35 a) is substantially uniform along the longitudinal direction. The value of the plate thickness of the reshapable section 3 is not particularly limited. In order to secure sufficient flexibility and appropriate strength, however, the plate thickness is preferably about 0.01 to 0.06 mm, more preferably about 0.02 to 0.04 mm.

While the grooves 31 a to 35 a are formed (formed substantially evenly) throughout the whole length of the reshapable section 3 in the configuration shown in the figures, this is not limitative. Thus, a plurality of grooves may be formed at a part in the longitudinal direction of the reshapable section 3. Examples of such a case include a configuration in which the grooves 34 a and 35 a in FIGS. 2 and 3 are omitted, and the grooves 31 a, 32 a and 33 a are formed only in an intermediate part and a distal part of the reshapable section 3.

In addition, while the grooves 31 a to 35 a are straight in plan-view shape as shown in FIG. 3, this configuration is not limitative. Thus, at least one of the grooves 31 a to 35 a may have a plan-view shape of a polygonal line such as V shape, W shape, etc. or a curved line such as arcuate shape, S shape, etc.

Furthermore, other groove(s) (not shown) through which arbitrary two or more of the grooves 31 a to 35 a communicate with each other may be provided.

Besides, while both edge parts of each of the grooves 31 a to 35 a in the reshapable section 3 are sharply shaped, this structure is not limitative. For example, both edge parts of each of the grooves 31 a to 35 a may be rounded in shape.

In the first wire 2, each of the distal-side constant outer diameter section 26, the constant outer diameter section 21 and the large diameter section 24 has a constant outer diameter along the longitudinal direction of the wire. The outer diameter of the distal-side constant outer diameter section 26 is substantially equal to the minimum outer diameter of the first tapered section 22, and the outer diameter of the constant outer diameter section 21 is substantially equal to the maximum outer diameter of the first tapered section 22 and is substantially equal to the minimum outer diameter of the second tapered section 23. The outer diameter of the large diameter section 24 is substantially equal to the maximum outer diameter of the second tapered section 23.

The distal end of the second wire 4 is joined to the proximal end of the first wire 2 (the proximal end of the large diameter section 24). The second wire 4 is included of a flexible or elastic wire material.

The method of joining the first wire 2 and the second wire 4 is not particularly limited. Examples of the joining method include welding such as friction welding, spot welding using a laser, butt resistance welding, e.g., upset welding, etc., and joining by use of a tubular joint member. Among these joining method, butt resistance welding is particularly preferred, since it can be carried out comparatively easily and it provides a high joint strength.

In the present embodiment, the second wire 4 is substantially constant in outer diameter. The outer diameter of the second wire 4 is substantially equal to the outer diameter of the large diameter section 24 of the first wire 2. This ensures that when the proximal end of the large diameter section 24 of the first wire 2 and the distal end of the second wire 4 are joined to each other, any step due to a difference in outer diameter between the wires 2 and 4 is not generated but a continuous surface can be obtained, at the outer periphery of the joint part (weld part) 6 of the wires 2, 4. Incidentally, in the present invention, this structure is not limitative. For example, the outer diameter(s) of the first wire 2 and/or the second wire 4 may vary across the joint part 6.

The mean outer diameter of the first wire 2 is smaller than the mean outer diameter of the second wire 4. This permits the guide wire 1 to be rich in flexibility on the first wire 2 disposed on the distal side and be comparatively high in rigidity on the second wire 4 disposed on the proximal side. Consequently, both flexibility at a distal part and excellent operationality (pushability, torque transmission performance, etc.) can be secured.

The materials constituting the first wire 2 and the second wire 4 are not particularly limited. Examples of the materials which can be used here include various metallic materials such as stainless steels (all species of SUS, e.g., SUS304, SUS303, SUS316, SUS316L, SUS316J1, SUS316J1L, SUS40S, SUS430, SUS434, SUS444, SUS429, SUS430F, SUS302), piano wire, cobalt alloys, pseudo-elastic alloys (inclusive of superelastic alloys), etc.

The material constituting the first wire 2 is preferably a pseudo-elastic alloy (inclusive of superelastic alloy), more preferably a superelastic alloy.

Superelastic alloys are rich in flexibility, have a restoring property, and have little tendency to undergo irreversible bending. Therefore, with the first wire 2 included of a superelastic alloy, the guide wire 1 can have sufficient flexibility and restoring property on bending, is enhanced in trackability in regard of complicatedly curved or bent blood vessels and the like, and can show more excellent operationality. In addition, even when the first wire 2 is subjected repeatedly to curving or bending deformations, the restoring property possessed by the first wire 2 prevents the first wire 2 from tending to undergo irreversible bending, so that it is possible to prevent the operationality of the guide wire 1 from being lowered due to a tendency to undergo irreversible bending acquired by the first wire 2 during the use of the guide wire 1.

The pseudo-elastic alloys include all of those showing tensile stress-strain curves of various shapes in which transformation points such as As, Af, Ms, Mf, etc. can or cannot be measured markedly. Thus, the pseudo-elastic alloys include all of those alloys which are largely deformed (strained) under a stress and will return substantially to their original shapes upon the removal of the stress.

Examples of the preferable composition of the superelastic alloy include NiTi alloys such as a Ni—Ti alloy containing 49 to 52 at. % of Ni, Cu—Zn alloys containing 38.5 to 41.5 wt. % of Zn, and Cu—Zn—X alloys containing 1 to 10 wt. % of X (X is at least one selected from among Be, Si, Sn, Al and Ga), and Ni—Al alloys containing 36 to 38 at. % of Al. Among these, particularly preferred are the Ni—Ti alloys. Incidentally, the superelastic alloys represented by the Ni—Ti alloys are excellent also in adhesion of a resin coating layer 8 which will be described later.

Cobalt alloys each show a high modulus of elasticity when formed into wires, and each have an appropriate elastic modulus. Therefore, a wire included of a cobalt alloy is excellent in torque transmission performance, and is extremely insusceptible to such problems as buckling. The cobalt alloy to be used here may be any alloy that contains Co as a constituent element; however, alloys containing Co as a main constituent (Co-based alloys, namely, alloys in which the content of Co by weight is the highest of the contents of constituent elements) are preferred, and Co—Ni—Cr alloys are more preferred. When an alloy with such a composition is used, the above-mentioned effect becomes more conspicuous. In addition, an alloy with such a composition has a high modulus of elasticity, and can be cold deformed notwithstanding the elastic limit set to be high. The high elastic limit makes it possible to reduce the wire diameter while sufficiently preventing generation of buckling, and therefore to obtain a guide wire having rigidity and flexibility sufficient for insertion to a desired site.

As the material constituting the second wire 4, the above-mentioned stainless steels are preferable. Stainless steels are higher in strength and rigidity than the above-mentioned superelastic alloys, and can therefore provide the guide wire 1 with excellent pushability and torque transmission performance.

The first wire 2 and the second wire 4 may be included of different materials, or may be included of the same metallic material or of metallic materials of the same type (alloys which contain the same main metallic elements). In the latter case, the joint part (weld part) 6 has a higher joint strength, so that even when the outer diameter of the joint part 6 is small, disconnection or the like is prevented and a good torque transmission performance and the like are displayed.

In the case where the first wire 2 and the second wire 4 are included of different materials, the first wire 2 is preferably included of the above-mentioned superelastic alloy, more preferably a Ni—Ti alloy, while the second wire 4 is preferably included of the above-mentioned stainless steel.

Incidentally, while the above description has been made as to a mode in which the first wire 2 and the second wire 4 are joined to each other, the guide wire may be composed of a single continuous wire body which is free of a joint part. In that case, examples of the material constituting the wire body include the same materials as above-mentioned, among which particularly preferred are the stainless steels, the cobalt alloys, and the pseudo-elastic alloys.

Around the outer periphery of a distal part of the wire body 10, a coil 5 is disposed so as to cover the distal part. With the coil 5 thus arranged, the area of contact of the wire body 10 with the inside wall of a catheter or the surface of a living body is reduced, whereby frictional resistance can be lowered. As a result, the guide wire 1 is further enhanced in operationality.

As shown in FIG. 1, the wire body 10 is inserted in a central part of the inside of the coil 5. In the present embodiment, the reshapable section 3, the transition section 27, the distal-side constant outer diameter section 26, the first tapered section 22, the whole part or part of the constant outer diameter section 21 are covered with the coil 5.

In addition, a distal part of the wire body 10 (particularly, the region ranging from the reshapable section 3 to the first tapered section 22) is inserted in the state of being out of contact with the inside surface of the coil 5. This results in that a gap 50 is formed between the coil 5 and the distal part of the wire body 10.

The coil 5 is obtained by helically forming a filament 54 which is circular in cross-sectional shape. In this case, the coil 5 may be composed of a single filament 54 wound helically or of a plurality of filaments 54 wound helically.

The material constituting the filament 54 is not particularly limited; for example, a metallic material or a resin material may be used. Examples of the metallic material include stainless steel, and radiopaque materials such as noble metals including Au, PT and the like, alloys contains those noble metals such as Pt—Ni alloys. In the latter case, radiopaqueness can be obtained at the distal part of the guide wire 1, and the guide wire 1 can be inserted into a living body while checking the position of the distal part under fluoroscopic observation, which naturally is preferable.

Incidentally, the coil 5 may be obtained by combining two or more materials. For example, a configuration may be adopted in which the filament 5 on the distal side of the coil 5 is included of a radiopaque material such as a Pt—Ni alloy whereas the filament 54 on the proximal side of the coil 5 is included of stainless steel. In this case, under fluoroscopic observation, the portion located on the distal side of the coil 5 (particularly, the portion including the reshapable section 3) can be exaggerated (can be visually checked more easily) as compared with the portion located on the proximal side thereof; therefore, the position of the distalmost portion of the guide wire 1 (the portion where the reshapable section 3 is present) can be visually checked more clearly.

In addition, the configuration in which the portion ranging from the reshapable section 3 to the constant outer diameter section 21 is covered with the coil 5 as shown in the figure is not limitative; for example, the reshapable section 3, the transition section 27, the distal-side constant outer diameter section 26, the first tapered section 22 and the constant outer diameter section 21 may be partly covered with the coil 5. In that case, it is preferable that the outer periphery of the reshapable section 3, at least, is covered with the coil 5.

Besides, where the coil 5 is arranged around the outer periphery of the reshapable section 3, the coil 5 may be touching or in secure contact with the reshapable section 3. In addition, such a coil 5 may be disposed for the purpose of imparting radiopaqueness to that portion of the guide wire 1 where the reshapable section 3 is present.

In addition, the wire diameter of the filament 54 of the coil 5 may be uniform throughout the whole length of the coil 5, or may have different values respectively on the distal side and on the proximal side of the coil 5. For example, the wire diameter of the filament 54 on the distal side of the coil 5 may be smaller (or larger) than that on the proximal side. This makes it possible to further enhance the flexibility of the guide wire 1 at a distal part of the coil 5.

Besides, the outer diameter of the coil 5 may be constant over the whole length of the coil 5, or may have different values respectively on the distal side and on the proximal side of the coil 5. For example, the outer diameter of the coil 5 on the distal side of the coil 5 may be smaller than that on the proximal side. This makes it possible to further enhance the flexibility of the guide wire 1 at a distal part of the coil 5.

In the present embodiment, the adjacent turns of the filament 54 of the coil 5 are in contact with each other, i.e., the coil 5 is in the state of the so-called close (tight) winding. The adjacent turns of the filament 54 exert a pressing force (compressive force) on each other in the axial direction of the wire body 10 in their natural condition. Here, the term “natural condition” means the condition where no external force is exerted. It is to be noted here, however, in the present invention this configuration is not limitative, and the adjacent turns of the filament 54 of the coil 5 may be spaced from each other in some part(s) of the coil 5.

As shown in FIG. 1, the coil 5 is fixed to the wire body 10 at three locations (a plurality of locations). Specifically, a distal part of the coil 5 is fixed to the distal end of the first wire 2 (the distal end of the reshapable section 3) by a fixing material (fixing part) 51, a proximal part of the coil 5 is fixed to an intermediate part (in the vicinity of the boundary between the constant outer diameter section 21 and the second tapered section 23) of the first wire 2 by a fixing material (fixing part) 53, and an intermediate part of the coil 5 is fixed to the first tapered section 22 of the first wire 2 by a fixing material (fixing part) 52. With the coil 5 fixed at such locations, parts of the coil 5 can be securely fixed to the wire body 10, without spoiling the flexibility of a distal part (the part where the coil 5 is present) of the guide wire 1.

Particularly, since the reshapable section 3 is fixed on the distal side (distal part) and the proximal side by the fixing materials 51 and 52, the reshapable section 3 can be assuredly fixed to the coil 5, so that the shape upon reshaping of the reshapable section 3 can be maintained appropriately.

The fixing materials 51, 52 and 53 are each preferably included of a solder (brazing filler metal). Incidentally, each of the fixing materials 51, 52 and 53 is not limited to a solder but may be an adhesive. In addition, the method of fixing the coil 5 to the wire body 10 is not limited to the use of the fixing material(s) but may be welding, for example. Besides, a distal end surface of the fixing material 51 is preferably rounded (see FIG. 1), in order to prevent the inside wall of a body lumen such as a blood vessel from damaging.

While the fixing material 52 is disposed on the first tapered section 22 in the configuration shown in the figure, this configuration is not limitative, and the fixing material 52 may be disposed at any intermediate portion of the coil 5, provided the portion is located on the proximal side of the reshapable section 3.

As shown in FIG. 1, the outside surface of the guide wire 1 is provided thereon with a resin coating layer 8 covering the whole part (or part) thereof. The resin coating layer 8 may be formed for any of various purposes. An example of the various purposes is to reduce the friction (sliding resistance) of the guide wire 1 and to enhance slidability, thereby enhancing the operationality of the guide wire 1.

In order to reduce the friction (sliding resistance) of the guide wire 1, the resin coating layer 8 is preferably included of a material capable of reducing friction as described below. This ensures that the frictional resistance (sliding resistance) between the guide wire 1 and the inside wall of a catheter used therewith is reduced, and the slidability of the guide wire 1 is enhanced, whereby the operationality of the guide wire 1 in the catheter is more enhanced. In addition, the lowering in the sliding resistance of the guide wire 1 ensures that, when the guide wire 1 is moved and/or rotated in a catheter, it is possible to more securely prevent the guide wire 1 from kinking (sharp bending) or torsion, particularly to more assuredly prevent a guide wire portion near the joint part 6 from kinking or torsion.

Examples of the material capable of reducing the friction include polyolefins such as polyethylene, polypropylene, etc., polyvinyl chloride, polyesters (PET, PBT, etc.), polyamides, polyimides, polyurethane, polystyrene, polycarbonate, silicone resins, fluororesins (PTFE, ETFE, etc.), and composite materials of these.

Besides, the resin coating layer 8 may be formed also for the purpose of enhancing safety in inserting the guide wire 1 into a blood vessel or the like. For this purpose, the resin coating material 8 is preferably included of a material rich in flexibility (soft material, elastic material).

Examples of the material rich in flexibility include polyolefins such as polyethylene, polypropylene, etc., polyvinyl chloride, polyesters (PET, PBT, etc.), polyamides, polyimides, polyurethane, polystyrene, silicone resins, thermoplastic elastomers such as urethane elastomers, polyester elastomers, polyamide elastomers, etc., various rubber materials such as latex rubbers, silicone rubbers, etc., and composite materials obtained by combining two or more of these.

Incidentally, the resin coating layer 8 may not necessarily be included wholly of the same material; namely, different materials may be used respectively on the distal side and on the proximal side of an intermediate part of the guide wire 1. For example, a configuration may be adopted in which the portion, covering the first wire 2 and the coil 5, of the resin coating layer 8 is included of the above-mentioned material rich in flexibility, whereas the portion, covering the second wire 4, of the resin coating layer 8 is included of the above-mentioned material capable of reducing friction.

In addition, the resin coating layer 8 may be a single layer or a laminate of two or more layers (for example, a laminate in which an inner layer is included of a material softer than the material constituting an outer layer). For example, a configuration may be adopted in which the portion, covering the first wire 2 and the coil 5, of the resin coating layer 8 is a single layer, whereas the portion, covering the second wire 4, of the resin coating layer 8 is a laminate of two or more layers, or vice versa.

The outer peripheral surface of the resin coating layer 8 as above may be provided with a groove or grooves (not shown). Particularly, it is preferable that at least the portion, corresponding to the reshapable section 3, of the resin coating layer 8 (the outer peripheral portion of the reshapable section 3) is provided with a groove or grooves in such a pattern as rectilinear shape, curved line shape, ring-like shape, spiral shape, net-like shape, etc. With such a groove or grooves provided, the flexibility of a distal part of the guide wire 1 is increased, and it is possible to reduce friction (sliding resistance) on the guide wire 1 and to further enhance slidability thereof.

Besides, the outside surface of at least a distal part of the guide wire 1 is preferably coated with a hydrophilic material. This ensures that the hydrophilic material when wetted comes to show lubricity, whereby the friction (sliding resistance) of the guide wire 1 is reduced and the slidability of the guide wire 1 is enhanced. As a result, the operationality of the guide wire 1 is enhanced.

Examples of the hydrophilic material include cellulose polymeric materials, polyethylene oxide polymeric materials, maleic anhydride polymeric materials (for example, a maleic anhydride copolymer such as methyl vinyl ether-maleic anhydride copolymer), acrylamide polymeric materials (for example, polyacrylamide, polyglycidyl methacrylate-dimethyl acrylamide (PGMA-DMAA) block copolymer), water-soluble nylon, polyvinyl alcohol, and polyvinyl pyrrolidone.

Such hydrophilic materials, in many cases, exhibit lubricity through wetting (absorption of water), thereby reducing the frictional resistance (sliding resistance) between the guide wire 1 and the inside wall of a catheter used therewith. As a result, the slidability of the guide wire 1 is enhanced, and the operationality of the guide wire 1 in the catheter will be better.

Second Embodiment

FIGS. 4 and 5 are respectively a side view and a plan view showing the configuration of a reshapable section of a guide wire according to the present invention (second embodiment).

Now, the second embodiment of the guide wire according to the present invention will be described below referring to these figures. The following description will be centered on the difference of the second embodiment from the first embodiment described above, and description of the same items as above will be omitted. Incidentally, for convenience of description, the right side in FIGS. 4 and 5 will be referred to as “proximal (side)”, the left side as “distal (side)”, the upper side in FIG. 4 as “upper (side)”, and the lower side as “lower (side)”.

The present embodiment is the same as the first embodiment above, except the configuration of the reshapable section 3.

As shown in FIGS. 4 and 5, the reshapable section 3 is plate-like in shape, and is provided with grooves similar to the above-mentioned in both sides of the plate-like shape thereof (the upper surface and the lower surface). The grooves formed in the upper surface (upper side) of the reshapable section 3 and the grooves formed in the lower surface (lower side) may be in the same pattern or in different patterns; in this embodiment, they are in different patterns.

To be more specific, in the present embodiment, five grooves 31 a, 32 a, 33 a, 34 a and 35 a the same as those described in the first embodiment above are formed in the upper surface of the reshapable section 3, and five grooves 31 b, 32 b, 33 b, 34 b and 35 b are formed in the lower surface of the reshapable section 3. In this case, the grooves 31 a to 35 a formed in the upper surface of the reshapable section 3 and the grooves 31 b to 35 b formed in the lower surface of the reshapable section 3 are formed alternately along the longitudinal direction of the reshapable section 3. Specifically, the grooves 31 a to 35 a and the grooves 31 b to 35 b are formed with a stagger therebetween of half their pitch along the longitudinal direction of the reshapabe section 3. Incidentally, the conditions such as the shapes, dimensions, intervals, etc. of the grooves 31 a-31 b are the same as or similar to those described with respect to the grooves 31 a to 35 a (refer to the description of the first embodiment above), and description of them is omitted here.

The configuration as above ensures that any portion in the longitudinal direction of the reshapable section 3 can be bent (deformed) to the upper side and the lower side freely and into a fine shape, so that the reshapable section 3 can wholly or partly be reshaped into a fine shape.

Incidentally, the grooves 31 a to 35 a formed in the upper surface of the reshapable section 3 and the grooves 31 b to 35 b formed in the lower surface of the reshapable section 3 may be the same or different in pattern, shape, dimensions (groove length, width, depth, etc.), intervals (pitch) and the like. For example, the grooves 31 a to 35 a and the corresponding grooves 31 b to 35 b may be provided at the same locations in the longitudinal direction of the reshapable section 3.

In addition, while the grooves 31 a to 35 a and the grooves 31 b to 35 b are formed (formed substantially evenly) over substantially the whole length of the reshapable section 3, this configuration is not limitative. For example, the lower surface (or the upper surface) of the reshapable section 3 may be provided with one groove or a plurality of grooves in a part in the longitudinal direction of the reshapable section 3. Examples of such a case include a configuration in which, of the grooves 31 b to 35 b in FIGS. 4 and 5, the grooves 34 b and 35 b are omitted, and the grooves 31 b, 32 b and 33 b are only formed in an intermediate part and a distal part of the reshapable section 3. In this case, the density of the grooves formed in the reshapable section 3 is higher on the distal side than on the proximal side, so that the reshapable section 3 can be reshaped into a more complicated shape or finer shape (for example, a more acutely curved or bent shape) on the distal side than on the proximal side.

Third Embodiment

FIGS. 6 and 7 are a side view and a plan view showing the configuration of a reshapable section of a guide wire according to the present invention (third embodiment).

Now, the third embodiment of the guide wire according to the present invention will be described below, referring to these figures. The following description will be centered on the difference of the third embodiment from the first and second embodiments above, and description of the same items as in the first and second embodiments will be omitted. Incidentally, for convenience of description, the right sides in FIGS. 6 and 7 will be referred to as “proximal (side)”, the left side as “distal (side)”, the upper side in FIG. 6 as “upper (side)”, and the lower side as “lower (side)”.

The present embodiment is the same as the second embodiment above, except the configuration of the reshapable section 3.

As shown in FIGS. 6 and 7, the reshapable section 3 is plate-like in shape, and is provided in the upper surface and the lower surface thereof respectively with grooves 31 a to 35 a and grooves 31 b to 35 b which are the same as or similar to those in the second embodiment.

In the second embodiment above, the plate width and the plate thickness of the reshapable section 3 have been uniform along the longitudinal direction of the reshapable section 3. In the third embodiment, on the other hand, the reshapable section 3 has a part where the plate width and the plate thickness gradually decrease (continuously decrease) along the distal direction. Specifically, in the part on the distal side of the groove 35 a of the reshapable section 3, the plate width and the plate thickness of the reshapable section 3 gradually decrease along the distal direction.

This configuration permits the reshapable section 3 to be reshaped more finely as the distal end thereof is approached. In other words, the reshapable section 3 can be reshaped into a more complicated or finer shape (for example, a more acutely curved or bent shape) on the distal side than on the proximal side.

Incidentally, while both the plate width and the plate thickness of the reshapable section 3 decrease gradually along the distal direction in this embodiment, this configuration is not limitative. Specifically, the reshapable section 3 may have a part where either one of the plate width and the plate thickness thereof decreases gradually along the distal direction.

In addition, while the plate width and the plate thickness of the reshapable section 3 decrease continuously along the distal direction, this is not limitative. Specifically, the reshapable section 3 may have a part where the plate width and/or the plate thickness thereof decreases stepwise along the distal direction.

Besides, the part where the plate width decreases along the distal direction and the part where the plate thickness decreases along the distal direction may not necessarily coincide with each other, and both of them may partly overlap each other, or both of them may not overlap each other. Examples of such a case include a configuration in which only the plate width decreases along the distal direction in a proximal part of the reshapable section 3, only the plate thickness decreases along the distal direction in a distal part of the reshapable section 3, and both the plate width and the plate thickness are decreased along the distal direction or are constant in an intermediate part of the reshapable section.

Fourth Embodiment

FIG. 8 is a plan view showing the configuration of a reshapable section of a guide wire according to the present invention (fourth embodiment).

Now, the fourth embodiment of the guide wire according to the present invention will be described below, referring to the figure. The following description will be centered on the difference of the fourth embodiment from the first embodiment above, and description of the same items as in the first embodiment will be omitted.

The present embodiment is the same as the first embodiment above, except the configuration of the reshapable section 3.

As shown in FIG. 8, the reshapable section 3 is plate-like in shape, and is provided in its upper surface (one side of the plate-like shape) with grooves 31 a to 35 a similar to those in the first embodiment. In the first embodiment, the grooves 31 a to 35 a have been extending in the direction parallel to the plate width direction of the reshapable section 3. In the fourth embodiment, on the other hand, the grooves 31 a to 35 a are each extending in a direction inclined at a predetermined angle to the plate width direction (the vertical direction in FIG. 8) of the reshapable section 3.

The inclination angles θ of the grooves 31 a to 35 a against the plate width direction may be the same or different. Examples of the latter case include a configuration in which the inclination angle θ increases (or decreases), continuously or stepwise, along the distal direction of the reshapable section 3.

The inclination angle (mean value) 0 is not particularly limited, and, normally, it is preferably about 5 to 70°, more preferably about 10 to 30°.

Incidentally, also in this embodiment, like in the second embodiment, both sides of the plate-like shape of the reshapable section 3 may be provided respectively with the grooves 31 a to 35 a and the grooves 31 b to 35 b. In this case, it is preferable that both the grooves 31 a to 35 a and the grooves 31 b to 35 b are each inclined at an inclination angle θ against the plate width direction of the reshapable section 3.

In addition, while the grooves 31 a to 35 a do not intersect in the configuration shown in FIG. 8, this is not limitative. For example, the groove formation pattern may be one in which all or some of the grooves intersect or are branched.

Fifth Embodiment

FIG. 9 is a side view showing the configuration of a reshapable section of a guide wire according to the present invention (fifth embodiment).

Now, the fifth embodiment of the guide wire according to the present invention will be described below referring to the figure. The following description will be centered on the difference of the fifth embodiment from the first and third embodiments described above, and description of the same items as above will be omitted.

The present embodiment is the same as the third embodiment, except the configuration of the reshapable section 3.

As shown in FIG. 9, the reshapable section 3 is plate-like in shape, and has a part where the plate width and the plate thickness gradually decrease (continuously decrease) along the distal direction. The part is provided in its upper surface and lower surface respectively with grooves 31 a to 35 a and grooves 31 b to 35 b which are the same as or similar to those in the third embodiment.

The grooves 31 a to 35 a and 31 b to 35 b are filled with a malleable metal 38. The malleable metal 38 is supplied into the grooves and secured to the inside surfaces of the grooves by such a method as flame spraying, welding, plating, vapor deposition, sputtering, etc.

When a bending stress is exerted on one of the portions provided with the grooves 31 a to 35 a and 31 b to 35 b (groove formed portions) of the reshapable section 3, the malleable metal 38 filling (secured to) the groove undergoes plastic deformation (spreading, compression or the like), resulting in that the groove formed portion as a whole is plastically deformed, and the shape upon the deformation is securely maintained. In other words, with the grooves 31 a to 35 a and 31 b to 35 b filled with the malleable metal 38, shape retention after deformation can be enhanced.

In the present embodiment, a configuration in which the malleable metal is secured to the whole body of the reshapable section 3 so as to render the whole part of the reshapable section 3 susceptible to plastic deformation is not adopted. Instead, a configuration is adopted in which the malleable metal is secured partly to the reshapable section so that only the groove formed portions are made to be susceptible to plastic deformation. By this it is possible to overcome the drawback of the former configuration, i.e., the problem that the whole part of the reshapable section 3 is hardened more than required, thereby lowering the flexibility or elasticity of a distal part of the guide wire 1.

Examples of the malleable metal 38 include Au and Au alloys (for example, Au—Cu alloys containing 1 to 50 wt. % of Cu, Au—Ag alloys containing 1 to 50 wt. % of Ag, and Au—Pt alloys containing 1 to 50 wt. % of Pt). Here, Au and Au alloys (particularly, Au—X alloys containing 1 to 50 wt. % of X, where X is at least one selected from among Cu, Ag and Pt) are excellent in malleability and in adhesion to the inside surfaces of the grooves 31 a to 35 a and 31 b to 35 b, and also in chemical stability, and are therefore preferable.

The amounts (weights) of the malleable metal 38 loaded in the grooves 31 a to 35 a and 31 b to 35 b may be the same or different. For example, the loading amount (weight) of the malleable metal 38 may be gradually increased or decreased along the distal direction of the reshapable section 3 (namely, sequentially in the order of the grooves 35 a, 35 b, 34 a, 34 b, 33 a, 33 b, 32 a, 32 b, 31 a and 31 b). In the former case (the amount is increased), the shape retention performance after deformation increases along the distal direction of the reshapable section 3; in the latter case (the amount is decreased), the shape retention performance after deformation increases along the proximal direction of the reshapable section 3.

In addition, the compositions of the malleable metals 38 placed to fill the grooves 31 a to 35 a and 31 b to 35 b may be the same or different. For example, a configuration may be adopted in which Au (pure gold) is used as the malleable metal 38 for the grooves 31 a, 31 b, 32 a, 32 b located comparatively on the distal side of the reshapable section 3, whereas an Au—X alloy or alloys containing 1 to 50 wt. % of X (for example, an Au—Cu alloy containing 1 to 50 wt. % of Cu) are used as the malleable metal(s) 38 for the other grooves 33 a, 33 b to 35 a, 35 b.

Incidentally, in the present invention, the configuration in which the malleable metal 38 is loaded in every one of the grooves 31 a to 35 a and 31 b to 35 b is not limitative; for example, a configuration may be adopted in which the grooves 31 a, 31 b, 32 a, 32 b located comparatively on the distal side are filled with the malleable metal(s) 38, whereas the other grooves 33 a, 33 b to 35 a, 35 b are not filled with the malleable metal 38.

In addition, the configuration in which all or some of the grooves are filled with the malleable metal(s) 38 can be applied, in the same manner, also to all the other embodiments than the fifth embodiments.

Sixth Embodiment

FIG. 10 is a side view showing the configuration of a reshapable section of a guide wire according to the present invention (sixth embodiment).

Now, the sixth embodiment of the guide wire according to the present invention will be described below referring to the figure. The following description will be centered on the difference of the sixth embodiment from the first embodiment above, and description of the same items as those in the first embodiment will be omitted.

As shown in FIG. 10, on the distal side of a first tapered section 22, a reshapable section 3 is formed as one body with the first tapered section 22. The reshapable section 3 is in the shape of a bar which is substantially circular in cross section (in the shape of a round bar). The bar-like reshapable section 3 has an advantage over the above-described plate-like reshapable section 3 in that it can be reshaped in a three-dimensional manner, i.e., it has a broad range of (a high degree of freedom in) selection of shape.

On the outer peripheral surface (outer surface) of such bar-like reshapable section 3 is provided with the grooves 31 a to 35 a similar to those in the first embodiment at intervals along the longitudinal direction of the reshapable section 3. In this case, in the reshapable section 3, the grooves 31 a to 35 a are formed partly in the outer peripheral portion of the reshapable section 3 (upper part of FIG. 10).

In the present embodiment, the conditions such as the shapes, dimensions, intervals, etc. of the grooves 31 a to 35 a are similar to those described in the first embodiment above, and, description of them is therefore omitted.

Incidentally, while the outer diameter of the reshapable section 3 is uniform along the longitudinal direction of the reshapable section 3 in the present embodiment, this is not limitative. For example, the outer diameter of the reshapable section 3 may be gradually decreased along the distal direction, i.e., the reshapable section 3 may be tapered, as shown in FIG. 14.

In addition, the cross-sectional shape of the bar-like reshapable section 3 is not limited to a circle but may be other shape, for example, an ellipse or a polygon such as a triangle, a tetragon (e.g., square, rhombus, trapezoid), a hexagon, a octagon, etc.

The outer periphery of a wire body 10 (first wire 2) is covered with a resin coating layer 9 similar to the above-mentioned resin coating layer 8, instead of the coil 5 in the first embodiment. Particularly, the outer periphery of the reshapable section 3 is covered with the resin coating layer 9. The thickness of the resin coating layer 9 is larger on the outer periphery of the reshapable section 3 than on that portion of the wire body 10 which is on the proximal side relative to the reshapable section 3. In addition, the distal end (tip) of the resin coating layer 9 is preferably rounded in shape.

Besides, the resin coating layer 9 may be formed also for the purpose of enhancing safety in inserting the guide wire 1 into a blood vessel or the like. For this purpose, the resin coating material 9 is preferably included of a material rich in flexibility (soft material, elastic material).

Examples of the material rich in flexibility include polyolefins such as polyethylene, polypropylene, etc., polyvinyl chloride, polyesters (PET, PBT, etc.), polyamides, polyimides, polyurethane, polystyrene, silicone resins, thermoplastic elastomers such as polyurethane elastomers, polyester elastomers, polyamide elastomers, etc., various rubber materials such as latex rubbers, silicone rubbers, etc., and composite materials obtained by combining two or more of these. Among these materials, particularly preferred are polyurethane, silicone resins, thermoplastic elastomers, and silicone rubbers.

Since the reshapable section 3 has the grooves 31 a to 35 a, when the resin coating layer 9 is provided, part of the material constituting the layer enters into the inside of the grooves 31 a to 35 a, thereby exhibiting an anchoring effect. Therefore, the adhesion of the resin coating layer 9 to the reshapable section 3 is high, so that delamination of the resin coating layer 9 is prevented even upon reshaping the reshapable section 3 into a desired shape.

Incidentally, in the present invention, the resin coating layer 9 may naturally be omitted.

Besides, though not shown in the figure, a coil similar to the above-mentioned coil 5 may be disposed around the outer periphery of the reshapable section 3. Such a coil is preferably wound in the state of touching or being in secure contact with the reshapable section 3. In addition, such a coil can be arranged for the purpose of imparting radiopaqueness to that portion of the guide wire 1 where the reshapable section 3 is present.

Seventh Embodiment

FIG. 11 is a side view showing the configuration of a reshapable section of a guide wire according to the present invention (seventh embodiment).

Now, the seventh embodiment of the guide wire according to the present invention will be described below referring to the figure. The following description will be centered on the difference of the seventh embodiment from the first and sixth embodiments above, and description of the same items as above will be omitted. Incidentally, for convenience of description, the upper side in FIG. 11 will be referred to as “upper (side)”, and the lower side as “lower (side)”.

The present embodiment is the same as the sixth embodiment, except the configuration of the reshapable section 3. The reshapable section 3 formed on the distal side of a first tapered section 22 is in the shape of a bar which is substantially circular in cross section (in the shape of a round bar), and is provided with a plurality of grooves in the outer peripheral surface thereof. In this case, of the reshapable section 3, a surface on one side (upper surface) and a surface on the other side (lower surface) opposite to each other, with the center axis of the reshapable section 3 therebetwen, are provided with the grooves in the same pattern.

To be more specific, the upper surface of the reshapable section 3 is provided with the grooves 31 a to 35 a similar to those in the sixth embodiment at intervals along the longitudinal direction of the reshapable section 3, and the lower surface of the reshapable section 3 is provided with the grooves 31 b to 35 b similar to the grooves 31 a to 35 a. The grooves 31 a to 35 a and the grooves 31 b to 35 b are formed in the same shape at the same positions in the longitudinal direction of the reshapable section 3.

The bar-like reshapable section 3 is comparatively high in rigidity, as compared with the plate-like reshapable section 3 mentioned above. However, since the reshapable section 3 is provided with the grooves 31 a to 35 a and the grooves 31 b to 35 b respectively on the one-side surface (upper surface) and the other-side surface (lower surface) opposite to each other, with the center axis of the reshapable section 3 therebetwen, the reshapable section 3 can be easily reshaped into a desired shape.

Incidentally, in this embodiment, also, as for a resin coating layer 9 and a coil disposed around the outer periphery of the reshapable section 3, which have been mentioned in the sixth embodiment above, the same as above-described is applicable.

Eighth Embodiment

FIG. 12 is a side view showing the configuration of a reshapable section of a guide wire according to the present invention (eighth embodiment).

Now, the eighth embodiment of the guide wire according to the present invention will be described below referring to the figure. The following description will be centered on the difference of this embodiment from the first, second and sixth embodiments above, and description of the same items as above will be omitted. Incidentally, for convenience of description, the upper side in FIG. 12 will be referred to as “upper (side)”, and the lower side as “lower (side)”.

The present embodiment is the same as the sixth embodiment, except the configuration of the reshapable section 3. The reshapable section 3 formed on the distal side of a first tapered section 22 is in the shape of a bar which is substantially circular in cross section (in the shape of a round bar), and is provided with a plurality of grooves in the outer peripheral surface thereof. In this case, of the reshapable section 3, a surface on the one side (upper surface) and a surface on the other side (lower surface) opposite to each other, with the center axis of the reshapable section 3 therebetween, are provided with the grooves in different patterns.

To be more specific, the upper surface of the reshapable section 3 is provided with the grooves 31 a to 35 a similar to those in the sixth embodiment at intervals along the longitudinal direction of the reshapable section 3, and the lower surface of the reshapable section 3 is provided with the grooves 31 b to 35 b equivalent to the grooves 31 a to 35 a, at positions in an alternate relashionship with the positions of the grooves 31 a to 35 a, that is, a stagger of half their pitch therebetween. In other words, the reshapable section 3 in the eighth embodiment is the same as the reshapable section 3 in the second embodiment, except that the reshapable section 3 here is bar-like in shape.

The bar-like reshapable section 3 is comparatively high in rigidity, as compared with the plate-like reshapable section 3 mentioned above. However, since the one-side surface (upper surface) and the other-side surface (lower surface) opposite to each other, with the center axis of the reshapable section 3 therebetween, are provided respectively with the grooves 31 a to 35 a and the grooves 31 b to 35 b in different patterns, any part in the longitudinal direction of the reshapable section 3 can be curved (deformed) freely to the upper side and to the lower side and into a fine shape, so that the reshapable section 3 can wholly or partly be reshaped more finely.

Incidentally, in this embodiment, also, a resin coating layer 9 and a coil disposed around the outer periphery of the reshapable section 3, which have been mentioned in the sixth embodiment above, the same as above-described is applicable.

Ninth Embodiment

FIG. 13 is a side view showing the configuration of a reshapable section of a guide wire according to the present invention (ninth embodiment).

Now, the ninth embodiment of the guide wire according to the present invention will be described below referring to the figure. The following description will be centered on the difference of this embodiment from the first and sixth embodiments above, and description of the same items as above will be omitted.

The present embodiment is the same as the sixth embodiment, except the configuration of the reshapable section 3. The reshapable section 3 formed on the distal side of a first tapered section 22 is in the shape of a bar which is substantially circular in cross section (in the shape of a round rod), and is provided in its outer peripheral surface with one or a plurality of spiral groove(s) 31 c. With such a spiral groove(s) 31 c provided, a distal part of the guide wire 1 can advantageously be rendered flexible.

The pitch of the groove 31 c (the interval between the adjacent groove portions as measured along the longitudinal direction of the reshapable section 3) may be uniform or varied along the longitudinal direction of the reshapable section 3. Examples of the latter case (a varying pitch) include a configuration in which the pitch of the groove 31 c decreases gradually along the distal direction of the reshapable section 3. In this case, the density of the groove portions formed in the reshapable section 3 is higher on the distal side than on the proximal side, so that the reshapable section 3 can be reshaped into a more complicated or finer shape (for example, a more acutely curved or bent shape) on the distal side than on the proximal side.

Incidentally, in this embodiment, also, a resin coating layer 9 and a coil disposed around the outer periphery of the reshapable section 3, which have been mentioned in the sixth embodiment above, the same as above-described is applicable.

Tenth Embodiment

FIG. 14 is a side view showing the configuration of a reshapable section of a guide wire according to the present invention (tenth embodiment).

Now, the tenth embodiment of the guide wire according to the present invention will be described below referring to the figure. The following description will be centered on the difference of this embodiment from the first and sixth embodiments above, and description of the same items as above will be omitted.

The present embodiment is the same as the sixth embodiment, except the configuration of the reshapable section 3. The reshapable section 3 formed on the distal side of a first tapered section 22 is in the shape of a bar which is substantially circular in cross section (in the shape of a round rod). In this case, the outer diameter of the reshapable section 3 gradually decreases in the distal direction, i.e., the reshapable section 3 is tapered. This ensures that the reshapable section 3 is gradually decreased in rigidity along the distal direction.

The reshapable section 3 as just-mentioned is provided in its outer peripheral surface with a plurality of annular (ring-shaped) grooves at intervals along the longitudinal direction of the reshapable section 3. Specifically, the reshapable section 3 is provided with the grooves 30 d, 31 d, 32 d, 33 d, 34 d and 35 d, in this order from the distal side.

In addition, of the grooves 30 d to 35 d, the groove pitch (the interval between the adjacent grooves) gradually decreases along the distal direction. This ensures that the density of the grooves formed in the reshapable section 3 is higher on the distal side than on the proximal side. This, together with the above-mentioned fact that the outer diameter of the reshapable section 3 gradually decreases in the distal direction, results in that the reshapable section 3 can be reshaped into a more complicated or finer shape (for example, a more acutely curved or bent shape) on the distal side than on the proximal side.

Incidentally, while the outer diameter of the reshapable section 3 is gradually varied along the longitudinal direction of the reshapable section 3, this is not limitative; for example, a configuration may be adopted in which the reshapable section 3 has a part where the outer diameter is varied stepwise (particularly, decreased stepwise along the longitudinal direction).

Besides, in this embodiment, naturally, the outer diameter of the reshapable section 3 may be uniform along the longitudinal direction, and the pitch of the grooves 30 d to 35 d may be constant along the longitudinal direction of the reshapable section 3.

Furthermore, in the present embodiment, also, as for a resin coating layer 9 described in the sixth embodiment and a coil disposed around the outer periphery of the reshapable section 3, which have been mentioned in the sixth embodiment above, the same as above-described is applicable.

In the present invention, the configuration in which the density of the grooves formed in the reshapable section 3 is varied along the longitudinal direction of the reshapable section 3, particularly the configuration in which the reshapable section 3 has a part where the density of the grooves increases along the distal direction, is applicable to all of the first to tenth embodiment described above.

In addition, in the present invention, naturally, the number, shapes, positions, etc. of the grooves in the reshapable section are not limited to those in the embodiment shown in the drawings. The grooves can also be formed in such patterns as a lattice-like pattern and a net-like pattern.

While the guide wire according to the present invention has been described above referring to the embodiments shown in the figures, the invention is not limited to the embodiments. The parts constituting the guide wire can be replaced by parts having arbitrary configurations which can exhibit functions the same as or equivalent to the above-mentioned functions. Besides, arbitrary structures may be added to the above-mentioned embodiments.

Furthermore, in the present invention, arbitrary two or more of the configurations according to the first to tenth embodiments described above may be combined, as required.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partial longitudinal sectional view (schematic side view) showing a first embodiment of the guide wire according to the present invention.

FIG. 2 is a side view of a reshapable section of the guide wire shown in FIG. 1.

FIG. 3 is a plan view of a reshapable section of the guide wire shown in FIG. 1.

FIG. 4 is a side view of a reshapable section in a second embodiment of the guide wire according to the invention.

FIG. 5 is a plan view of a reshapable section in a second embodiment of the guide wire according to the invention.

FIG. 6 is a side view of a reshapable section in a third embodiment of the guide wire according to the invention.

FIG. 7 is a plan view of a reshapable section in a third embodiment of the guide wire according to the invention.

FIG. 8 is a plan view of a reshapable section in a fourth embodiment of the guide wire according to the invention.

FIG. 9 is a side view of a reshapable section in a fifth embodiment of the guide wire according to the invention.

FIG. 10 is a side view of a reshapable section in a sixth embodiment of the guide wire according to the invention.

FIG. 11 is a side view of a reshapable section in a seventh embodiment of the guide wire according to the invention.

FIG. 12 is a side view of a reshapable section in an eighth embodiment of the guide wire according to the invention.

FIG. 13 is a side view of a reshapable section in a ninth embodiment of the guide wire according to the invention.

FIG. 14 is a side view of a reshapable section in a tenth embodiment of the guide wire according to the invention.

DESCRIPTION OF REFERENCE SYMBOLS

-   1 Guide wire -   10 Wire body -   2 First wire -   21 Constant outer diameter section -   22 First tapered section -   23 Second tapered section -   24 Large diameter section -   26 Distal-side constant outer diameter section -   27 Transition section -   3 Reshapable section -   31 a to 35 a Groove -   31 b to 35 b Groove -   31 c Groove -   30 d to 35 d Groove -   36, 37 Portion -   38 Malleable metal -   4 Second coil -   5 Coil -   50 Gap -   51, 52, 53 Fixing material (fixing part) -   54 Filament -   6 Joint part (weld part) -   8, 9 Resin coating layer 

1. A guide wire comprising: a wire body comprised of a plurality of sections including an elongate reshapeable section, an elongate constant diameter section and an elongate tapering section; the constant diameter section having an outer diameter that is constant along an entirety of a longitudinal extent of the constant diameter section; the tapering section having an outer diameter that tapers from a larger outer diameter to a smaller outer diameter toward the reshapeable section; the constant outer diameter section and the tapering section both being positioned proximally of the reshapeable section; the elongate reshapeable section being made of a superelastic alloy and possessing an outer circumferential surface; and a plurality of spaced apart grooves formed in the outer circumferential surface of the reshapeable section, each groove extending around less than half the outer circumferential surface of the reshapeable section, and each groove extending in a direction different from the longitudinal direction of the reshapeable section.
 2. The guide wire as set forth in claim 1, wherein the reshapeable section is plate-shaped having oppositely positioned sides, the grooves being provided in only one of the sides of the plate-shaped reshapeable section.
 3. The guide wire as set forth in claim 1, wherein the reshapeable section is plate-shaped having oppositely positioned sides, the grooves being provided in both sides of the plate-shaped reshapeable section.
 4. The guide wire as set forth in claim 1, wherein the reshapeable section is bar-shaped, the grooves being provided on only one side of the bar-shaped reshapeable section,
 5. The guide wire as set forth in claim 1, wherein the reshapeable section is bar-shaped, the grooves being provided on opposite sides of the bar-shaped reshapeable section, the grooves on one side of the reshapeable section being positioned in aligned relation to the grooves on the opposite side of the reshapeable section along the longitudinal direction of the reshapeable section.
 6. The guide wire as set forth in claim 1, wherein the reshapeable section is bar-shaped, the grooves being provided on opposite sides of the bar-shaped reshapeable section, the grooves on one side of the reshapeable section being positioned in staggered relation to the grooves on the opposite side of the reshapeable section along the longitudinal direction of the reshapeable section.
 7. A guide wire comprising: a wire body comprised of a proximal part and a distal part, the distal part being located distally of the proximal part; an elongate reshapeable section provided at the distal part of the wire body, the elongate reshapeable section extending in a longitudinal direction and possessing an outer surface; and the outer surface of the reshapeable section being provided with a plurality of grooves extending in a direction different from the longitudinal direction of the reshapeable section.
 8. The guide wire as set forth in claim 7, wherein the reshapeable section is plate-shaped having oppositely positioned sides, the grooves being provided in at least one of the sides of the plate-shaped reshapeable section.
 9. The guide wire as set forth in claim 8, wherein at least a part of the reshapeable section possesses a thickness and/or a width that decreases in the distal direction.
 10. The guide wire as set forth in claim 8, wherein at least a part of the reshapeable section possesses a thickness and/or a width that decreases continuously in the distal direction.
 11. The guide wire as set forth in claim 7, wherein the reshapeable section is plate-shaped having oppositely positioned sides, the grooves being provided on both of the oppositely positioned sides of the plate-shaped reshapeable section.
 12. The guide wire as set forth in claim 11, wherein the grooves on one of the sides of the reshapeable section are positioned in aligned relation, along the longitudinal direction of the reshapeable section, to the grooves on the opposite side of the reshapeable section.
 13. The guide wire as set forth in claim 12, wherein at least a part of the reshapeable section possesses a thickness and/or a width that decreases in the distal direction.
 14. The guide wire as set forth in claim 11, wherein the grooves on one of the sides of the reshapeable section are positioned in staggered relation, along the longitudinal direction of the reshapeable section, to the grooves on the opposite side of the reshapeable section.
 15. The guide wire as set forth in claim 14, wherein at least a part of the reshapeable section possesses a thickness and/or a width that decreases in the distal direction.
 16. The guide wire as set forth in claim 7, wherein the reshapeable section is bar-shaped having an outer circumference, the grooves being provided on only one side of the bar-shaped reshapeable section, each of the grooves extending around less than half the outer circumference of the bar-shaped reshapeable section.
 17. The guide wire as set forth in claim 7, wherein the reshapeable section is bar-shaped having an outer circumference, the grooves being provided on opposite sides of the bar-shaped reshapeable section, each of the grooves extending around less than half the outer circumference of the bar-shaped reshapeable section, the grooves on one side of the reshapeable section being positioned in aligned relation to the grooves on the opposite side of the reshapeable section along the longitudinal direction of the reshapeable section.
 18. The guide wire as set forth in claim 17, wherein at least a part of the reshapeable section possesses an outer diameter that decreases in the distal direction.
 19. The guide wire as set forth in claim 7, wherein the reshapeable section is bar-shaped having an outer circumference, the grooves being provided on opposite sides of the bar-shaped reshapeable section, each of the grooves extending around less than half the outer circumference of the bar-shaped reshapeable section, the grooves on one side of the reshapeable section being positioned in staggered relation to the grooves on the opposite side of the reshapeable section along the longitudinal direction of the reshapeable section.
 20. The guide wire as set forth in claim 19, wherein at least a part of the reshapeable section possesses an outer diameter that decreases in the distal direction.
 21. The guide wire as set forth in claim 7, wherein at least some of the grooves are filled with a malleable material.
 22. The guide wire as set forth in claim 7, wherein each of the plurality of grooves is oriented at an angle other than 0° and 180° to a central axis of the guide wire.
 23. A guide wire comprising: a wire body comprised of a proximal part and a distal part, the distal part being located distally of the proximal part; an elongate reshapeable section provided at the distal part of the wire body, the elongate reshapeable section being bar-shaped and possessing a circular cross-sectional shape, the bar-shaped reshapeable section extending in a longitudinal direction and possessing an outer surface; and the outer surface of the reshapeable section being provided with a spiral groove. 